The dental restoration of a partially or wholly edentulous patient with artificial dentition is typically done in two stages. In the first stage, an incision is made through the gingiva to expose the underlying bone. After a series of drill bits creates an osteotomy in the bone, a dental implant is placed in the jawbone for osseointegration. The dental implant generally includes a threaded bore to receive a retaining screw holding mating components therein. During the first stage, the gum tissue overlying the implant is sutured and heals as the osseointegration process continues.
Once the osseointegration process is complete, the second stage is initiated. Here, the gum tissue is re-opened to expose the end of the dental implant. A healing component or healing abutment is fastened to the exposed end of the dental implant to allow the gum tissue to heal therearound. Preferably, the gum tissue heals such that the aperture that remains generally approximates the size and contour of the aperture that existed around the natural tooth that is being replaced. To accomplish this, the healing abutment attached to the exposed end of the dental implant has the same general contour as the gingival portion of the natural tooth being replaced.
During the typical second stage of dental restoration, the healing abutment is removed and an impression coping is fitted onto the exposed end of the implant. This allows an impression of the specific region of the patient's mouth to be taken so that an artificial tooth is accurately constructed. After these processes, a dental laboratory creates a prosthesis to be permanently secured to the dental implant from the impression that was made.
In addition to the more traditional system for placing dental implants described above, some systems use guided placement of the dental implants. To do so, a surgical guide is placed in the patient's mouth at a known location. The surgical guide includes openings for providing the exact placement of drill bits used to create the osteotomy. Once the osteotomy is completed, the surgical guide may permit the dental implant to be placed through the same opening and enter the osteotomy that was guided by the surgical guide.
Surgical guides are typically created based on a dental scan (e.g., using a computed tomography (“CT”) scanner) of the patient's mouth. A CT scanner provides the details of the patient's bone tissue, jawbone, and remaining teeth so that the surgical guide may be developed based on computer-aided design (“CAD”) and computer-aided manufacturing (“CAM”). One example of the use of a CT scanner is disclosed in U.S. Patent Publication No. 2006/0093988 to Swaelens et al. (“Swaelens”), which is herein incorporated by reference in its entirety. Swaelens also describes the use of various tubes that may be placed within a surgical guide to receive the drill bits and implants. One example of the use of a CT-scan to develop a surgical plan involving a surgical guide is disclosed in U.S. Patent Application Ser. No. 61/003,407, filed Nov. 16, 2007, and described in Biomet 3i's Navigator™ system product literature, “Navigator™ System For CT Guided Surgery Manual” that is publicly available, both of which arc commonly owned and herein incorporated by reference in their entireties. Another example of the use of a CT-scan to develop a surgical plan is disclosed in U.S. Patent Publication No. 2006/0093988, which is herein incorporated by reference in its entirety.
CT scans tend to produce highly precise data for hard tissue (such as bone tissue or teeth) but produce less precise data for soft tissue (such as the gingival tissue). Thus, existing 3-D anatomic digital models and surgical guides typically do not accurately account for the gingival tissue overlying the patient's jawbone. Other techniques for acquiring gingival tissue data, such as using a barium sulfate-infused scanning appliance, are time and/or labor intensive and are often not particularly accurate.
Other methods are typically used to produce accurate soft tissue data. For example, soft tissue data may be acquired by taking an impression of the inside of a patient's mouth, using an intra-oral scanner, or the like. These methods, however, fail to provide accurate data relating to the hard tissue of the patient's mouth and, therefore, cannot be leveraged to improve the quality of the 3-D anatomic digital models and subsequent surgical guides created using these models.
When considering the dental and/or surgical plan for a specific patient, the maximum depth of the distal end of the dental implant within the bone is important so that the sinus cavity and mandibular canal may be avoided. Additionally, the location of the implant(s) relative to the gingival surface and underlying bone is important, especially one that involves the placement of several dental implants. Thus, it is important that precise data relating to both the hard tissue (e.g., bone structure and teeth) and the soft tissue (e.g., gingival tissue) of the patient's mouth is obtained and used to create a 3-D anatomic digital model from which the surgical guide may be developed.
Thus, there exists a need to develop an improved method for creating a highly accurate digital model that incorporates accurate data relating to both the hard tissue and the soft tissue of the patient's mouth and that forms an accurate basis from which to create a surgical model, a subsequent surgical guide, and/or custom abutments.